Transmission fluid change how to/ write up for FJ60? (2 Viewers)

[SteveH]

Be sure to check the small vent on the top of your transfer case, and preferably remove the little cap and rubber disk, and slide 3/8" fuel line over the remaining stub, clamp it on with a hose clamp, and run this 5' piece of hose up the firewall. This gives you a free-breathing transfer case.

You never want pressure or vacuum in your transfer case, and the transmission vents through the shift tower (which is why it doesn't need a vent, per se).

 

[JoeK9]

Be sure to check the small vent on the top of your transfer case, and preferably remove the little cap and rubber disk, and slide 3/8" fuel line over the remaining stub, clamp it on with a hose clamp, and run this 5' piece of hose up the firewall. This gives you a free-breathing transfer case.

You never want pressure or vacuum in your transfer case, and the transmission vents through the shift tower (which is why it doesn't need a vent, per se).

What does extending the vent actually do? Also will oil come out of the 5' hose?

 

[SteveH]

The vent is designed to let the transfer case burp out air when the case gets hot and the air expands. It also keeps out water. The oil level in the transfer case is well below this vent system, by design.

But, the problem is that the rubber disk gets oil on it over time and glues itself to the top of the vent nipple. When this happens, air cannot get out and you get slight pressure in your transfer case when it's hot. This can push the oil into the transmission through a weak seal, or out on the ground through the output seals.

When you remove this valve and replace it with a long hose, you let the air (not oil) breathe in and out of the transfer case, as dictated by its temperature. The hose is run up high to the firewall (hence 5' long) so that if you dunk the transfer case under water, you won't suck in water. Attach a cheap fuel filter in the vent end of the hose.

No oil should ever come out of this vent hose, unless your truck is upside down or on its side, in which case, it will be a secondary problem.

 

[JoeK9]

The vent is designed to let the transfer case burp out air when the case gets hot and the air expands. It also keeps out water. The oil level in the transfer case is well below this vent system, by design.

But, the problem is that the rubber disk gets oil on it over time and glues itself to the top of the vent nipple. When this happens, air cannot get out and you get slight pressure in your transfer case when it's hot. This can push the oil into the transmission through a weak seal, or out on the ground through the output seals.

When you remove this valve and replace it with a long hose, you let the air (not oil) breathe in and out of the transfer case, as dictated by its temperature. The hose is run up high to the firewall (hence 5' long) so that if you dunk the transfer case under water, you won't suck in water. Attach a cheap fuel filter in the vent end of the hose.

No oil should ever come out of this vent hose, unless your truck is upside down or on its side, in which case, it will be a secondary problem.

Thanks for the detail, super clear.
Mental note - upside down = bad..

 

[MKinMT1996]

This thread has helped me immensely however I wanted to double check that I can use 80w-90 oil in both the transmission and transfer case in my 60? Any brand better than others? I assume I just fill both to the top until oil starts to trickle out? Thanks for the help!!

 

[OSS]

I wanted to double check that I can use 80w-90 oil in both the transmission and transfer case

Yes that oil is fine
Yes fill it until it overflows
There are some fancy synthetic 75w-90 gear oils that people like (Redline MT-90) but any 80w90 gear oils is fine that meets GL4 spec.

See attached for the Toyota maintenance manual

 

[MKinMT1996]

Much appreciated OSS.!!

 

[MKinMT1996]

One more follow-up... front and rear differentials use the same oil and fill until it trickles out?

Need roughly 8 Qts all together?

Thanks

 

[OSS]

3.2 qts front
2.6 qts rear
Yes fill till it dribbles out

If the transmission/transfer case oil is GL4/GL5 it can be used in the differentials too.
Differentials need a GL5 gear oil.

Specifications are noted in the manual linked above.

 

[Spike Strip]

Just an FYI, make sure your FILL plug is able to be removed before draining. Goes for both Trans and T'case.

 

[shipmag]

and if oil comes out of the transmission fill plug that's not good. The transfer case front seal is gone. 500 other people have found a hose I now sell lets that oil drain back into the transfer case. Check out this thread from classifieds.

Transmission to Transfer Case Bypass Hose

Go to last thread for current pricing. The first 5 group buys were done at this url Tranny to Transfer case bypass hose if you want to know the history or look up how others have done with this product click on the link. I am now ready to open group buy 6. As I am only ordering 5 at a time my...

forum.ih8mud.com

Shipmag
Hagler Technology LLC

 

[MKinMT1996]

Ordered a 12.75. Looks like a super slick design. shipmag was great to work with!

 

[euclid537]

He said he’s sold 500 of them, you're good to go!

 

[MKinMT1996]

Anyone running this gear oil? Doesn't look to be synthetic. I assume that is still ok?? Thanks for the help!

 

[MKinMT1996]

I was able to drain and fill both differentials, t-case and tranny fluid but now have a leak that wasn’t there before at what I think is the transfer case oil seal. Is it something that may stop or if it’s leaking is the seal shot? Thanks for any help!

 

[ChaserFJ60]

Your fluid was probably too low before to make it leak fresh. I wouldnt wait for the leak to stop it may be a sign of something that needs to be addressed.
Even though it may be unlikely I would first verify the bearing is okay in the output flange. there should be absolutely no play in the left/right - up/down - in/out of the flange. Some rotational play is okay. If all is well then its probably just a seal. It can be a PITA but its doable. I got parts from @cruiseroutfit awhile ago and did this same job.

I would buy a new stake nut while your in there

 

[MKinMT1996]

@ChaserFJ60 thanks for the info!!!! Makes sense about the fluid level. I will do some searching for a thread on this maintenance.

 

[MKinMT1996]

That is the transfer case oil seal correct? Just want to make sure I am searching for the correct part and a thread on how to do it!
Thanks

 

[ChaserFJ60]

That is the transfer case oil seal correct? Just want to make sure I am searching for the correct part and a thread on how to do it!
Thanks

Yeah I think so, Its the output flange ring seal

 

[2mbb]

The transfer case has a front and rear rotating seal associated with each output shaft. The one you show looks like the front, but it's hard to tell from your picture. If you drive around mostly in 2wd, the front drive shaft doesn't turn so much and that seal may develop a flat spot. You could try locking both wheel hubs (this will make the front differential and drive shaft rotate, even though you are in 2wd). Having the shaft rotate may make the leak go away or make it worse.

Clean the transfer case around the seal. drive around some with the wheel hubs locked and monitor the leak. If you need to replace the seal, the instructions are attached.

It doesn't seem too hard. You will need a way to hold the companion flange from rotating while you remove the lock nut. the SST shown is just a metal bar with holes so it can bolt onto the companion flange.

You might be able to carefully pry the seal out with a flat screw driver or pry bar. Seal driver kits can be found cheap at harbor freight or probably on amazon.